Spray head



Sept. 20, 1932. J. c. MacLAcl-ILAN 1,878,538

SPRAY HEAD, A

Filed June 1a. 1931 2 sheets-'sheet 1 1/ KD .,..u..,.. kill i F SPRAYHEAD Filed June 18, 1931 2 Sheets-Sheet 2 Patented Sept. 20, 1932 UNITEDSTATES PATENT OFFICE l JOHN C. MACLACHLAN, OF CHICAGO, ILLINOIS,.ASSIGNOR TO 'DEE-HY PRODUCTS COM- PANY, OF CHICAGO, ILLINOIS, ACORPORATION OF ILLINOIS SPRAY HEAD Application led June 18, 1931. SerialNo. 545,223.

This invention relates to a drying apparavhead taken along the lineII-II of Fig. 3,

tu's for drying liquids or semi-liquid material and partcularly to adistributing head for such an apparatus.

As is well known, such drying apparatus is now used for drying milk,buttermilk, blood, fruit juices, and various other liquids. In thepresent type of apparatus the liquid is dried by being discharged into adrying chamber in a very iine condition and dried by heated air passingthrough said chamber. In drying whole milk and other colloidal liquids,it is desirable that the liquid be dividedY as tinely as possiblewithout impact as the impact tends to coagulate the at and otherglobules in the milk and to prevent the dried product from going readilyinto solution.

In the previously used types of apparatus, the milk, or other liquid isdistributed centrifugally by a discharging head which is drven atveryhigh speed. If a single disc is used, it is necessary to have quite alarge diameter to secure the necessary peripheral speed for throwing thematerial outwardly to divide the same, and it is necessary to drive thedisc at extremely high speed.

Previously, I have invented a distributing or spray head which, in ameasure, overcomes this diiiiculty. It is disclosed in my U. S. PatentNo. 1,742,478. This was a decided improvement over methods then in usebut-there was still a chance for the impact of a small percentage of theparticles, this impact being between the particles and portions of thesucceeding blade in the spray head.

It is an object of this invention, therefore, to provide a spray headwhich will distribute the liquid with substantially no impact betweenany of the spray particles and any surface of its revolving members.

This and other objects and advantages of the invention will be fully setforth in the following description made in connection with theaccompanying drawings, in which similar reference characters refer tosimilar parts throughout the several views, and in which;

Figure 1 is a vertical sectional view through the drying cabinet of thedrying apparatus;

Figure 2' is a sectional view of the drying with parts in elevation;Figure 3 is a sectional view taken along the line III-III of Figure 2,with parts in elevation.

Referring to the drawings, a drying apparatus is shown comprising acabinet 1 hav ing walls 2, said cabinet being of polygonal shape incross-section or of cylindrical shape. The cabinet is shown as havingreceiving hoppers or compartments 3 at its bottom with converging bottomwalls having discharge outlets 4. The cabinet 1 has a top 5 throughwhich projects a distributing apparatus 6. The liquid to be vaporized isfed through a pipe 7 to a rotating head forming a part of saiddistributing apparatus 6. -An inclined wall 9 extends about the uppercorner of the cabinet forming a chamber 10 through which some of theentering-air passes. Said wall has openings 11 therethroughcommunicating with chamber 10. A. rod 12 is shown extending around thewall 2 adjacent to its upper end, lfrom which issuspended a fabric orflexible curtain 13. The drying air is supplied at the bottom of thecabinet and substantially at the center thereof by a conduit 14, abovewhich is a conical deflector 15 surrounded by a cylinder 16. Saidcylinder 16 is open at its upper end` but has a bar 17 across its topforming one of the bearings for the deflector 15. The cabinet 1 or thewall 2 thereof has a plurality of discharge open- 22, a distributingmember 23, and a ring 24 which supports the fan blades 25. The bellshaped member 22'is internally threaded at its upper end to engage thelower end of the tube 21. Its middle portion is enlarged to form thechamber 26 and its lower portion is fiared to form the bell shapedportion 42 and the two series of blades 28 and 29. The ring 24 isadjustably mounted on the member 22 by means of the set-screws 30. Theblades 25 are adjustably held in said ring 24 by means of set-screws 31.A recess or groove 32 is rovided in each of said fan blades 25 direct yunder. set-screws 31 to prevent the blades from coming out of the ring24 if the set-screws should become loose during operation.

The two series of blades 28 and 29, the exact construction of whichforms an important feature of my invention, are staggered with respectto each other, the series 28 being bent out more than series 29. Each ofthese blades is substantially flat on its lower side but the top surfaceisrounded off so that the outer edge.33 is relativel sharp. Said seriesof blades 28 and 29 are evelled along each radial edge, forming surfacesas at`34 and 35. These blades are so formed that their inner orouter'surfaces will generate surfaces rather than solids when the headis rotated about its axis, as when it is in operation. In this respect,my present invention diilers radically from that disclosed in my U. S.Patent No. 1,742,478, the blades in that invention being tilted so as toproduce a strong current of air. Slits 36 occurring between the twoseries of blades 28 and 29 serve the purposeof allowing suitableproportions of the current of air from the fan blades 25 to pass by theedges of the blades thereby atomizing or dispersing the liquid,producing very fine droplets.

The portion of the bell shaped member 22, occurring just under thechamber 26 is internally threaded to support the distributing member 23.Said distributing member 23, shown partly in cross-section and partly inrelief, (Fig. 3) comprises a ring portion 37, which is threadedexternally to engage with said bell shaped member 22. A cone shapedportion 38 is formed on a disk shaped portion 39 of said distributingmember 23. Said ring portion 37 is formed integrally with the coneshaped portion 38, to which it is attached by means of a series ofspaced lugs 40 between which occur the openings 41.

In operation, the head will be disposed in the drying chamber as shownin Fig. 1 and said head will be rotated at high speed, say about 3,000to 5,000 revolutions per minute.

The liquid to be sprayed is fed into the pipe7. On leaving the lower endof said pipe it comes into contact with the cone 38 and escapes throughthe openings 41 between thevdisk 39 and the ring portion 37. The highspeed of rotation causes this liquid to be thrown outwardly anddownwardly, coming into contact with the under surface of the portion 42of the member 22 at such a small angle that the im act is not in any wayinjurious to the llquid. The liquid travels down ,the inner surface ofthe blades 28 and 29 of the member 22 and finally is thrown off theirends and edges.

The novel staggered position of the blades, fully explained above,allows all articles to get free from the edge of one bla e before thenext blade comes into a position for contact with the particles, so thatthere is n0 such destruction of the colloid particles as would renderthe dried materialmuch less soluble than it otherwise would be. At thesame time the air current created by the fan blades 25 is passing.downwardly through the openings 36 between the blades 28 and 29 of themember 22 and over the outer edges of the blades 28 and 29.I 4

Adjustment may be made of the air current created by the fan blades 26by loosening the set-screws 31 and rotatingeach blade until the desiredpitch is produced and ti ht- `ening said screw. Adjustment of the helghtof the fan bladesl 26 above the blades 28 and 29 may be made in asimilar manner by means of the set-screws 30. Also, it is under someconditions desirable to place a cylinder 27 (Fig. 1) over or around thedevice so as to direct the air current against the blades 28 and 29 withgreater force. This current of air divides the liquid into very minuteparticles which will dry quickly yby virtue of their small size.

The general operation of a dehydrating cell like that shown in Figure 1will be readily understood by anyone skilled in the art, and since itdoes not form a part of the resent invention, it will not be describedere. I have set forth the general principles of this method of spraydrying more fully in my United States Letters Patent No. 1,742,478.

From the foregoing description, it will be seen that I have made adistinct improvement in the apparatus forI spray. drying liquid byproviding a devicewhereby liquid may be vaporized without impact of theglobules, with its consequent detrimental ef-` fect on the subsequentsolubility of the dried product.

I am aware that many changes may be made and numerous details ofconstruction may be varied through a wide range without departing fromthe principles of this invention, and I, therefore, do not purposelimiting the patent granted hereon otherwise than necessitated by theprior art.

I claim as my invention:

l. A distributing head for a liquid dehydration cell, comprising arotatable member having blades alternately lying in substantiallyconical surfaces and means for feeding films of liquid along the innerfaces of said blades to be thrown therefrom by'centrifugal I force andatomized by currents of air passing dration cell, comprising a rotatablemember having closely spaced blades, alternate blades lying in slightlydivergent conical surfaces, and means for feeding films of a liquid ontothe inner surfaces of said blades for distribution therefromwithoutsubstantial impact against said blades.

3. A distributing head for a liquid dehydration cell,.comprising arotatable member having closel spaced blades, alternate blades lying inslig tly divergent conical surfaces, means for feeding films of a liquidonto the inner surfaces of said blades for distribution therefromwithout substantial impact against said blades and means for directing acurrent of air against the outside surfaces of said blades and betweensaid blades to effect atomization of said liquid films.

4. In a distributing head for a liquid dehydration cell, arotatable"member having closely spaced blades presenting surfaces lyingalmost completely within substantially conical surfaces, means forfeeding a liquid to said blade surfaces, other blades revoluble withsaid member and a sleeve surrounding said other blades to directcurrents of air against the outer surfaces of said first mentionedblades.

5. In a distributing head for a liquid dehydration cell, a rotatablemember having closely spaced blades presenting surfaces lying almostcompletely within substantially conical surfaces, means for feeding aliquid to said blade surfaces, including a feed pipe and a conicaldistributer spaced from the open end of said pipe and adjacent saidblade surfaces and other blades revoluble with said member to directcurrents of air against the outer surfaces of said first mentionedblades.

6. In a distributing head for a liquid dehydration cell, a rotatablemember having closely spaced blades presenting surfaces lyingalmostcompletely within substantially conical surfaces, means for feeding aliquid to said blade surfaces, including a feed pipe and a conicaldistributer spaced from the open end of said pipe and adjacent saidblade surfaces, other blades revoluble with said member and a sleevesurrounding said other blades to direct currents of air against thelouter surfaces of said first mentioned blades.

7. In a liquid dehydration cell, a distributing head positioned in thetop wall thereof kand dependent therefrom comprising a rotatable tube,an inner liquid feed pipe terminating within said tube, a member securedto said tube and having closely spaced outwardly and downwardly slopingblades, fan

blades secured to said member above said other blades, an open-endedsleeve secured to and surrounding said fan blades and means spaced fromthe open end of said feed pipe for distributing liquid over the innersurfaces of said first mentioned blades.

8. In a liquid dehydration cell, a distributing head positioned in thetop wall thereof and dependent therefrom comprising a rotatable tube, amember secured to said tube and having closely spaced outwardly. anddownwardly sloping blades, fan blades secured to said member, above saidother blades, and being adjustable as to pitch and also adjustable as aunit on said tube relative to said first mentioned blades, an innerliquid feed pipe terminating within said member, and means spaced fromthe open end of said feed pipe for distributing liquid over the innersurfaces of said first mentioned blades.

9. In a liquid dehydration cell, a distributing head positioned in thetop wall thereof and dependent therefrom comprising a rotatable tube, amember secured tosaid tube and having closely spaced outwardly anddownwardly sloping blades, alternate blades. lying in slightly divergentconical surfaces, fan blades secured to said member above said otherblades, an open-ended sleeve surrounding said fan-blades, an innerliquid feed pipe terminating within said member and means spaced fromthe open end of said feed pipe for distributing liquid over the innersurfaces of said first mentioned blades.

10. The method of drying milk which comprises distributing .the samecentrifugally on a surface to. form a thin film, distributing said filmwithout impact onto a plurality of discontinuous surfaces lying inslightly divergent coaxial cones, revolving said surfaces at high speedand causino air to pass downwardly between said surfaces to separatesaid milk into nely divided condition as it is thrown from said surfacescentrifugally.

11. The method of drying milk which com-` prises distributing said milkcentrifugally in a thin film or layer, transferring said film withoutimpact to a system of discontinuous surfaces lying in slightly divergentcoaxial cones, causing air to pass in a downwardlyl directed stream athigh velocity over and between said vsurfaces to separate said milk intofinely divided condition as it is thrown from said surfaces.

12. The method of drying colloidal liquids which comprises distributingthe same onto the under side of a system of discontinuous surfaces,staggered with respect to each other and arranged about a central axisand revolving at high speed about said axis, causing the liquid to bedistributed centrifugally from said surfaces, and causing a current ofair to pass downwardly over and between said surfaces thereby breakingthe liquid into numerous small droplets.

13. A distributing head comprising a rotatable flared member havingdivided slopmg surfaces which unite to form a single 1anA conicalsurface toward their upper ends and divide into two alternating setsstaggered with respect'to each other at their lower ends and means forfeeding a iilm of liquid to the inside surface of said member fordistribution over said surfaces substantially ,without impact. l

In testimony whereof I have hereunto sub-- scribed my name at Chicago,Cook County,

Illinois.

JOHN Cm MAOLACHLAN.

